Telephone Wiring Mystery

[croy]

I bought a new, modular, twin-telephone-jack outlet box cover, and bridged the two jacks to be in parallel.

I added wire-stubs to furnish twist-together jumpers for the incoming wire (easier to add the stubs on the bench, than to deal with the screw-connectors, crouched in a dark corner).

I wanted to check continuity, so I cut a modular cord in half and bared the wires on one half so I could use an ammeter to check.

What I found was that black & yellow are reversed, and red & green are reversed. The colors are that way on the plate that I bought (short wires with forked terminals in the ends, under the screw-heads). Is this normal? Does it make a difference? It seems to me that if it didn't make any difference, there would be no point to having four wire colors--two of one color, and two of another color would do it.

[hrhofmann]

By forked terminals do you mean spade lugs? Ar you sure you didn't make the reversal when you made the measurements. Looking at things from the front, they are opposite than when looking at them from the back.

That said, you can usually reverse R + G, and Bl + Yel. Without knowing what you are connecting, it is impossible to say for 100% surety. For example, some pots telephones will not work if their polarity is reversed. You can answer, and can listen and talk, but the touchpad to output touchtones will not work. Other phones have internal bridges that solve that problem.

[croy]

I suppose. The kind where you only need to loosen the screw to get the terminal free.

Just going by color. My improvised patch cord has the same colors as the colors that came in the cover plate.

Telephone and computer DSL line.

[mike]

Not exactly sure how you have it wired. Or where you are. In the USA, red/green is what most people use. The black/yellow is for a second phone line.

Are you sure your cable is wired with the proper colors?

[DA]

Telephone equipment transmits balanced signals - i.e. only the voltage difference between the two wires matters for its operation, not the actual polarity (which is very often flipped, just like in your case). In other words, it will work.

The yellow and black wires are for a second line. If you don't have a second phone line, just disregard the yellow/black pair.

[gfretwell]

There are 4 ways you can crimp on the RJ plugs and the people who make up cords only care about 2 (reversing polarity or straight through) The phone really doesn't care unless it is an old genuine Bell/Western Electric phone with the mechanical ringer and touch tone. They won't "tone" wired backward.

[Stormin Mormon]

Or, power for lighted dial.

Christopher A. Young Learn more about Jesus

.

The black/yellow is for a second phone line.

[homeowner]

That was probably designed to be used for a DUAL phone system. (Two phone lines). R + G are always the first phone line, and Y + B are the second line.

Since you wanted both jacks on the same line, you had to change the wires. So what's the problem?

[homeowner]

Geeezzzzz, I dont think they've made lighted dial phones since the

1960s.

[Stormin Mormon]

They havn't used tip and ring nomenclature, for that time, also.

Christopher A. Young Learn more about Jesus

.

Geeezzzzz, I dont think they've made lighted dial phones since the

1960s.

[croy]

Nope. It was just a modular extension cord that I could afford to cut in half and bare the wires, allowing me to check color to color with an ammeter.

I installed it, and it, and both DSL modem and the telephone seem to be working fine.

[croy]

One of the phones *is* an old "Princess" model, with lighted pushbuttons in the handset, and a real bell for a ringer. It seems to be working fine.

[hrhofmann]

Then you must have lucked out and got the right connections. IF you want to experiment, reverse the two wire going to the princess phone and see if you can still touchtone. I'm not sure if it will still work or not.

[clare]

Or any other "line powered" feature.

[clare]

They mis-named the jack, in that case.

[gfretwell]

The Princess Phone It's little It's lovely and it lights!

[gfretwell]

Yup, when was the last time you saw a phone jack in a phone system? (where tip and ring came from)

[PV]

The last intercom I installed used "tip and ring" terminology, that was last May

[micky]

I still have one, however. A pink princess phone, with a dial. . (I"m still looking for a pink princess) . For a while I actually had the transformer in the basement and ran the light off t he black and yellow.

[micky]

You know, I just learned that on sci.electronics.repair.

I've been using the terms for about 50 years, and I thought the ring was the wire the ring came in on, and the tip was the other one, maybe because it tipped some circuit when the voltage got high enough.

I only figured it out this past summer when I asked about what turned out to be callled a TRR plug, a tip, ring, ring plug.